Methods and apparatuses for default spatial relation information determination

ABSTRACT

A method, performed by a User Equipment (UE), includes receiving, from a cell, configuration signaling configuring the UE with one or more PUCCH resources on an active UL BWP, the one or more PUCCH resources not being configured with PUCCH-SpatialRelationInfo, and the configuration signaling indicating that a default spatial relation behavior for PUSCH transmission scheduled by a DCI format 0_0 is enabled; receiving, from the cell, the DCI format 0_0 on an active DL BWP, the DCI format 0_0 providing scheduling information for a PUSCH; and transmitting the PUSCH according to the default spatial relation behavior which determines a spatial relation with reference to a QCL-TypeD RS corresponding to a QCL assumption of a pre-determined CORESET on the active DL BWP of the cell.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation of U.S. patent application Ser. No.17/085,468 filed on Oct. 30, 2022, which claimed the benefit of andpriority to provisional U.S. Patent Application Ser. No. 62/929,287,filed on Nov. 1, 2019, entitled “Default Spatial Relation InformationDetermination based on DL Quasi-Colocation.” The above-identifiedapplication is herein incorporated by reference in its entirety.

FIELD

The present disclosure generally relates to wireless communications, andmore particularly, relates to methods and apparatuses for defaultspatial relation information determination.

BACKGROUND

With the tremendous growth in the number of connected devices and therapid increase in user/Network (NW) traffic volume, various efforts havebeen made to improve different aspects of wireless communication for thenext-generation wireless communication system, such as thefifth-generation (5G) New Radio (NR), by improving data rate, latency,reliability, and mobility.

The 5G NR system is designed to provide flexibility and configurabilityto optimize the NW services and types, accommodating various use casessuch as Enhanced Mobile Broadband (eMBB), Massive Machine-TypeCommunication (mMTC), and Ultra-Reliable and Low-Latency Communication(URLLC).

However, as the demand for radio access continues to increase, there isa need for further improvements of wireless communication for thenext-generation wireless communication system.

SUMMARY

The present disclosure is directed to methods and apparatuses fordefault spatial relation information determination.

According to an aspect of the present disclosure, a UE is provided. TheUE includes a memory and at least one processor coupled to the memory.The at least one processor is configured to receive, from a cell,configuration signaling configuring the UE with one or more PUCCHresources on an active UL BWP, the one or more PUCCH resources not beingconfigured with PUCCH-SpatialRelationInfo, and the configurationsignaling indicating that a default spatial relation behavior for PUSCHtransmission scheduled by a DCI format 0_0 is enabled; receive, from thecell, the DCI format 0_0 on an active DL BWP, the DCI format 0_0providing scheduling information for a PUSCH; and transmit the PUSCHaccording to the default spatial relation behavior which determines aspatial relation with reference to a QCL-TypeD RS corresponding to a QCLassumption of a pre-determined CORESET on the active DL BWP of the cell.

According to another aspect of the present disclosure, a method,performed by a User Equipment (UE), for default spatial relationinformation determination is provided. The method includes receiving,from a cell, configuration signaling configuring the UE with one or morePUCCH resources on an active UL BWP, the one or more PUCCH resources notbeing configured with PUCCH-SpatialRealtionInfo, and the configurationsignaling indicating that a default spatial relation behavior for PUSCHtransmission scheduled by a DCI format 0_0 is enabled; receiving, fromthe cell, the DCI format 0_0 on an active DL BWP, the DCI format 0_0providing scheduling information for a PUSCH; and transmitting the PUSCHaccording to the default spatial relation behavior which determines aspatial relation with reference to a QCL-TypeD RS corresponding to a QCLassumption of a pre-determined CORESET on the active DL BWP of the cell.

According to yet another aspect of the present disclosure, a method,performed by a base station, for default spatial relation informationdetermination is provided. The method includes transmitting, to a UE,configuration signaling configuring the UE with one or more PUCCHresources on an active UL BWP, the one or more PUCCH resources not beingconfigured with PUCCH-SpatialRelationInfo. and the configurationsignaling indicating that a default spatial relation behavior for PUSCHtransmission scheduled by a DCI format 0_0 is enabled; transmitting, tothe UE, the DCI format 0_0 on an active DL BWP, the DCI format 0_0providing scheduling information for a PUSCH; and receiving the PUSCH,from the LE, according to the default spatial relation behavior whichdetermines a spatial relation with reference to a QCL-TypeD RScorresponding to a QCL assumption of a pre-determined CORESET on theactive DL BWP of the cell.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the followingdetailed description when read with the accompanying figures. Variousfeatures are not drawn to scale. Dimensions of various features may bearbitrarily increased or reduced for clarity of discussion.

FIG. 1 illustrates a list of spatial relation information configured forPhysical UL Control Channel (PUCCH) operations, in accordance with animplementation of the present disclosure.

FIG. 2 illustrates multiple Sounding Reference Signal (SRS) resourcesets each configured with a pathloss reference RS resource, inaccordance with an implementation of the present disclosure.

FIG. 3 illustrates a flowchart for a method by a UE for default spatialrelation information determination, in accordance with an implementationof the present disclosure.

FIG. 4 illustrates a flowchart for a method by a base station fordefault spatial relation information determination, in accordance withan implementation of the present disclosure.

FIG. 5 illustrates a block diagram of a node for wireless communication,in accordance with various aspects of the present disclosure.

DESCRIPTION

The following description contains specific information pertaining toexemplary implementations in the present disclosure. The drawings in thepresent disclosure and their accompanying detailed description aredirected to merely exemplary implementations. However, the presentdisclosure is not limited to merely these exemplary implementations.Other variations and implementations of the present disclosure willoccur to those skilled in the art. Unless noted otherwise, like orcorresponding elements among the figures may be indicated by like orcorresponding reference numerals. Moreover, the drawings andillustrations in the present disclosure are generally not to scale, andare not intended to correspond to actual relative dimensions.

The following description contains specific information pertaining toexample implementations in the present disclosure. The drawings in thepresent disclosure and their accompanying detailed description aredirected to merely example implementations. However, the presentdisclosure is not limited to merely these example implementations. Othervariations and implementations of the present disclosure will occur tothose skilled in the art. Unless noted otherwise, like or correspondingelements among the figures may be indicated by like or correspondingreference numerals. Moreover, the drawings and illustrations in thepresent disclosure are generally not to scale, and are not intended tocorrespond to actual relative dimensions.

For consistency and ease of understanding, like features are identified(although, in some examples, not illustrated) by numerals in the examplefigures. However, the features in different implementations may differin other respects, and thus shall not be narrowly confined to what isillustrated in the figures.

References to “one implementation,” “an implementation.” “exampleimplementation,” “various implementations,” “some implementations,”“implementations of the present disclosure,” etc., may indicate that theimplementation(s) of the present disclosure so described may include aparticular feature, structure, or characteristic, but not every possibleimplementation of the present disclosure necessarily includes theparticular feature, structure, or characteristic. Further, repeated useof the phrase “in one implementation,” “in an example implementation,”or “an implementation,” do not necessarily refer to the sameimplementation, although they may. Moreover, any use of phrases like“implementations” in connection with “the present disclosure” are nevermeant to characterize that all implementations of the present disclosuremust include the particular feature, structure, or characteristic, andshould instead be understood to mean “at least some implementations ofthe present disclosure” includes the stated particular feature,structure, or characteristic. The term “coupled” is defined asconnected, whether directly or indirectly through interveningcomponents, and is not necessarily limited to physical connections. Theterm “comprising.” when utilized, means “including, but not necessarilylimited to”; it specifically indicates open-ended inclusion ormembership in the so-described combination, group, series, and theequivalent.

The term “and/or” herein is only an association relationship fordescribing associated objects, and represents that three relationshipsmay exist, for example, A and/or B may represent that: A exists alone. Aand B exist at the same time, and B exists alone. “A and/or B and/or C”may represent that at least one of A, B and C exists. In addition, thecharacter “/” used herein generally represents that the former andlatter associated objects are in an “or” relationship.

Additionally, for the purpose of non-limiting explanation, specificdetails, such as functional entities, techniques, protocols, standards,and the like, are set forth for providing an understanding of thedescribed technology. In other examples, a detailed description ofwell-known methods, technologies, systems, architectures, and the likeare omitted so as not to obscure the description with unnecessarydetails.

Persons skilled in the art will immediately recognize that any NWfunction(s) or algorithm(s) described in the present disclosure may beimplemented by hardware, software, or a combination of software andhardware. Described functions may correspond to modules that may besoftware, hardware, firmware, or any combination thereof. The softwareimplementation may comprise computer-executable instructions stored oncomputer-readable media such as memory or other types of storagedevices. For example, one or more microprocessors or general-purposecomputers with communication processing capability may be programmedwith corresponding executable instructions and carry out the describedNW function(s) or algorithm(s). The microprocessors or general-purposecomputers may be formed of Applications Specific Integrated Circuitry(ASIC), programmable logic arrays, and/or using one or more DigitalSignal Processor (DSPs). Although some of the example implementationsdescribed in this specification are oriented to software installed andexecuting on computer hardware, nevertheless, alternative exampleimplementations implemented as firmware or as hardware or combination ofhardware and software are well within the scope of the presentdisclosure.

The computer-readable medium includes but is not limited to RandomAccess Memory (RAM), Read-Only Memory (ROM), Erasable ProgrammableRead-Only Memory (EPROM), Electrically Erasable Programmable Read-OnlyMemory (EEPROM), flash memory. Compact Disc Read-Only Memory (CD-ROM),magnetic cassettes, magnetic tape, magnetic disk storage, or any otherequivalent medium capable of storing computer-readable instructions.

A radio communication NW architecture (e.g., a Long Term Evolution (LTE)system, an LTE-Advanced (LTE-A) system, or an LTE-Advanced Pro system)typically includes at least one Base Station (BS), at least one UE, andone or more optional NW elements that provide connection towards an NW.The UE communicates with the NW (e.g., a Core NW (CN), an Evolved PacketCore (EPC) NW, an Evolved Universal Terrestrial Radio Access NW(E-UTRAN), a Next-Generation Core (NGC), or an Internet), through aRadio Access NW (RAN) established by the BS.

It should be noted that, in the present disclosure, a UE may include,but is not limited to, a mobile station, a mobile terminal or device, auser communication radio terminal. For example, a UE may be a portableradio equipment, which includes, but is not limited to, a mobile phone,a tablet, a wearable device, a sensor, or a Personal Digital Assistant(PDA) with wireless communication capability. The UE is configured toreceive and transmit signals over an air interface to one or more cellsin a RAN.

A BS may include, but not limited to, a Node B (NB) as in the UniversalMobile Telecommunication System (UMTS), an evolved Node B (eNB) as inthe LTE-A, a Radio NW Controller (RNC) as in the UMTS, a Base StationController (BSC) as in the Global System for Mobile communications(GSM)/GSM EDGE Radio Access NW (GERAN), an ng-eNB as in an E-UTRA BS inconnection with the SGC, a next-generation Node B (gNB) as in the 5GAccess NW (5G-AN), and any other apparatus capable of controlling radiocommunication and managing radio resources within a cell. The BS mayconnect to serve the one or more UEs through a radio interface to theNW.

A BS may be configured to provide communication services according to atleast one of the following Radio Access Technologies (RATs): WorldwideInteroperability for Microwave Access (WiMAX), GSM (often referred to as2G), GERAN, General Packet Radio Service (GPRS), UMTS (often referred toas 3G) based on basic Wideband-Code Division Multiple Access (W-CDMA),High-Speed Packet Access (HSPA), LTE, LTE-A, enhanced LTE (eLTE), NR(often referred to as 5G), and LTE-A Pro. However, the scope of thepresent disclosure should not be limited to the protocols mentionedabove.

The BS may be operable to provide radio coverage to a specificgeographical area using a plurality of cells included in the RAN. The BSmay support the operations of the cells. Each cell is operable toprovide services to at least one UE within its radio coverage. Morespecifically, each cell (often referred to as a serving cell) mayprovide services to serve one or more UEs within its radio coverage,(e.g., each cell schedules the Downlink (DL) and optionally ULJresources to at least one UE within its radio coverage for DL andoptionally UL packet transmissions). The BS may communicate with one ormore UEs in the radio communication system through the plurality ofcells. A cell may allocate sidelink (SL) resources for supportingproximity service (ProSe). Each cell may have overlapped coverage areaswith other cells. In MR-DC cases, the primary cell of a Master CellGroup (MCG) or a Secondary Cell Group (SCG) may be called as a SpecialCell (SpCell). A Primary Cell (PCell) may refer to the SpCell of an MCG.A PSCell may refer to the SpCell of an SCG. MCG refers to a group ofserving cells associated with the Master Node (MN), comprising theSpCell and optionally one or more secondary cells (SCells). SCG refersto a group of serving cells associated with the Secondary Node (SN),comprising of the SpCell and optionally one or more SCells.

As discussed above, the frame structure for NR is to support flexibleconfigurations for accommodating various next generation (e.g., 5G)communication requirements, such as eMBB, mMTC, and URLLC, whilefulfilling high reliability, high data rate, and low latencyrequirements. The orthogonal frequency-division multiplexing (OFDM)technology, as agreed in the 3^(rd) Generation Partnership Project(3GPP), may serve as a baseline for an NR waveform. The scalable OFDMnumerology, such as the adaptive sub-carrier spacing, the channelbandwidth, and the cyclic prefix (CP), may also be used. Additionally,two coding schemes are considered for NR: (1) low-density parity-check(LDPC) code and (2) polar code. The coding scheme adaption may beconfigured based on the channel conditions and/or service applications.

Moreover, it is also considered that in a transmission time interval ofa single NR frame, at least DL transmission data, a guard period, and ULtransmission data should be included, where the respective portions ofthe DL transmission data, the guard period, the UL transmission datashould also be configurable, for example, based on the NW dynamics ofNR. In addition, SL resources may also be provided in an NR frame tosupport ProSe services.

The NR system may support beam management for enabling, but not limitedto, high-frequency band (e.g., millimeter-wave frequency band)communication. To combat higher pathloss in a high-frequency band, abeamforming technique is adopted for providing additional gain, with thecost of reduced spatial coverage for signal transmission and reception.To make up for the lost spatial coverage of beamforming, a beam issteered towards different directions in Time Division Multiplexing (TDM)manner so that after a certain period of time, the UE or the gNB canstill learn its environment with a desired spatial coverage.

In NR, for example. Release-15 (Rel-15), beam management is supported bya Transmission Configuration Indication (TCI) framework and spatialrelation information for DL and UL, respectively. For DL, differenttypes of a Qusai-CoLocation (QCL) assumption are indicated. Among them,QCL-type D is related to spatial receiving characteristics that may beused by a UE for receiving a target RS or channel. In the UL direction,the spatial transmitting characteristic may be indicated to the UE viathe spatial relation information provided from the NW side. A UE mayperform UL transmission for UL channel(s) and signal(s) accordingly.

For a UE with beam correspondence, DL beam management procedures thatmay involve DL beam measurement and reporting may provide enoughinformation for selecting a suitable UL beam for UL transmission. Inthis case, not only the UL beam sweeping procedure can be saved, butalso the UL beam indication signaling. However, such an UL operationmode is not yet introduced in NR Rel-15, for example based on TS 38series of specifications with version V15.6.0.

To save UL beam indication signaling for, e.g., an UL control channel(e.g., PUCCH), an UL data channel (e.g., Physical UL Shared Channel(PUSCH)), or an UL (Sounding Reference Signal) for at least beamcorrespondent UE, enabling default spatial relation information for theconcerned UL channel(s)/signal(s) for a beam correspondent UE based onthe DL QCL assumption may be needed. In NR Rel-15 (e.g., TechnicalSpecification (TS)38.214 V15.5.0), a QCL assumption for the DemodulationRS (DM-RS) ports of a Physical DL Shared Channel (PDSCH) of a servingcell may be determined based on the QCL parameters of the CORESET(s)configured to a UE. More specifically, the QCL assumption of the DM-RSports of a PDSCH of a serving cell may be determined based on thefollowing text in Table 1:

TABLE 1 If a DL scheduling offset of scheduling DL Control Information(DCI) is larger than a threshold (timeDurationForQCL)  If TCI indicationfield is not provided in the scheduling DCI   QCL assumption for thePDSCH is identical to the QCL assumption   whichever is applied for theCORESET used for the transmission of Physical   DL Control Channel(PDCCH) corresponding to the scheduling DCI.  If TCI indication field isprovided in the scheduling DCI   QCL assumption for the PDSCH isdetermined based on the TCI field in the   scheduling DCI. If the DLscheduling offset of the scheduling DCI is less or equal to a threshold(timeDurationForQCL)  The UE may assume that QCL parameters of PDSCH ofthe serving cell are  identical to the QCL parameter(s) used for thePDCCH QCL indication of the  CORESET associated with a monitored searchspace with the lowest CORESET  identifier (CORESET-ID) in the latestslot in which one or more CORESETs  within the active Bandwidth Part(BWP) of the serving cell are monitored by the  UE. When PDSCH and itsscheduling PDCCH are in different Component Carriers (CCs), if the DLscheduling offset of the scheduling DCI is less or equal to a thresholdtimeDurationForQCL or if the TCI information is absent from thescheduling DCI,  The UE obtains its QCL assumption for the scheduledPDSCH from the  activated TCI state with the lowest ID applicable to thePDSCH in the active  BWP of the scheduled cell.

However, in order to enable the spatial relation information of a PUCCHand/or the spatial relation information of an SRS to follow QCLparameters of a CORESET, at least one of the following dimensions (i) to(vi) may also be considered:

-   -   (i) PUCCH resources may be grouped, and the default spatial        relation information determination for PUCCH may be PUCCH        resource group-based.    -   (ii) DL CORESETs may be grouped, with a CORESET group        corresponding to, e.g., the same Transmit-Receive Point (TRP).        The default spatial relation information determination for a        PUCCH/SRS may correspond to different CORESET groups.    -   (iii) SRS resource set configured with usage: {codebook,        nonCodebook, antennaSwitching} may need to be differentiated.    -   (iv) Pathloss reference RS for UL power control may be        configured in different manners for PUCCH resources and for SRS        resources. Default spatial relation information determination        may take this part into account.    -   (v) Periodic(P)/semi-persistent (SP)/aperiodic (AP) PUCCH        transmissions may follow different behavior for determining        default spatial relation information.    -   (vi) Default spatial relation information determination may        differentiate itself between self-carrier scheduling and        cross-carrier scheduling.

In addition, since spatial relation information of a PUSCH may beindicated implicitly or explicitly via the spatial relation informationof a PUCCH or SRS, modification to PUSCH spatial relation informationdetermination may also be made accordingly.

It should be understood that a spatial relation may be conceptualized asa spatial domain transmission filter or a beam. Thus, in the presentdisclosure, the terms “spatial relation.” “spatial domain transmissionfilter,” and “beam” may be utilized interchangeably.

1. Default Spatial Relation for PUCCH

For PUCCH operations, a LE may be configured with at least one spatialrelation (or “spatial domain transmission filter”) via Radio ResourceControl (RRC) signaling (e.g., an RRC configuration) from a BS. Eachspatial domain transmission filter may be indicated by a correspondingspatial relation information parameter (e.g., an Information Element(IE) denoted as PUCCH-SpatialRelationInfo) in the RRC configuration. Inaddition, the spatial relation information parameter may also indicate aDL pathloss reference RS for estimating DL pathloss for UL PUCCH powercontrol purposes. For example, the spatial relation informationparameter may include (or may be associated with) an IE denoted aspucch-PathlossReferenceRS.

For each PUCCH resource, its corresponding spatial domain transmissionfilter may be selected from the spatial domain transmission filter(s)configured to the UE, and activated via Medium Access Control(MAC)-Control Element (CE) activation signaling from the BS.

FIG. 1 illustrates a list of spatial relation information configured forPUCCH operations, in accordance with an implementation of the presentdisclosure.

As illustrated in FIG. 1 , a UE may be configured with a list 108 ofspatial relation information via RRC signaling from a BS. The list 108of spatial relation information may include one or morePUCCH-SpatialRelationInfo IEs (e.g., PUCCH-SpatialRelationInfo #1 toPUCCH-SpatialRelationInfo #N, where N is a natural number), where eachPUCCH-SpatialRelationInfo IE may be used to indicate or determine aspatial domain transmission filter or a beam for PUCCH operations. Forexample, for transmission of a PUCCH resource, the UE may select one ofthe PUCCH-SpatialRelationInfo IEs in the list 108 to apply (e.g., basedon the MAC-CE activation signaling from a BS). As illustrated in FIG. 1, the UE may be instructed by the BS (e.g., via the MAC-CE activationsignaling) to use/apply the spatial domain transmission filter indicatedby the PUCCH-SpatialRelationInfo IE #1 to transmit the PUCCH resource102, and use/apply the spatial domain transmission filter indicated bythe PUCCH-SpatialRelationInfo IE #3 to transmit the PUCCH resource 104and the PUCCH resource 106.

In addition, each PUCCH-SpatialRelationInfo IE in the list of spatialrelation information may indicate a corresponding (DL) pathlossreference RS resource (not illustrated). For example, eachPUCCH-SpatialRelationInfo IE in the list of spatial relation informationmay include (or be associated with) an indication of a pathlossreference RS resource.

If the UE is configured with only one spatial domain transmission filter(e.g., there is only one PUCCH-SpatialRelationInfo IE in the list 108),the present spatial domain transmission filter in the list (e.g., thelist 108) may be used for the transmissions of the PUCCH resources(e.g., PUCCH resources 102, 104 and 106) allocated to the UE without theMAC-CE activation signaling.

In one implementation, the PUCCH resource may be used in a P/SP/APmanner. For example, a P/SP PUCCH resource may be used for P/SP ChannelState Information (CSI) reporting, and an AP PUCCH resource may be usedfor Hybrid Automatic Repeat reQuest (HARQ)-Acknowledgement (ACK)feedback transmission(s).

An AP PUCCH transmission may be triggered by DC from a BS. The DCI maybe transmitted by the BS in a DL Component Carrier (CC) paired with anUL CC where the AP PUCCH transmission takes place (self-carrierscheduling), or in a DL CC not paired with the UL CC where the AP PUCCHtransmission takes place (cross-carrier scheduling). Supplementary UL(SUL) operations may be considered as self-carrier scheduling in thiscase.

In one implementation, a UE may determine a spatial domain transmissionfilter for a PUCCH resource without explicit signaling from a BS. Forexample, a UE may apply a default spatial domain transmission filter fora PUCCH resource when the UE cannot acquire thePUCCH-SpatialRelationInfo IE from NW signaling (e.g., signaling from theBS).

In one implementation, the default spatial domain transmission filter(s)for individual PUCCH resources allocated to a UE may be determinedindependently.

In one implementation, the PUCCH resources may be grouped as one or morePUCCH resource groups. In this case, the default spatial domaintransmission filter may be determined for each PUCCH resource groupindependently.

In one implementation, the grouping of the PUCCH resources may be formedimplicitly or explicitly based on NW signaling.

In one implementation, the PUCCH resources associated with different UEpanels may correspond to different PUCCH resource groups.

In one implementation, a PUCCH resource group is associated with aCORESET group. The association may be via a higher layer signaling(e.g., RRC signaling). For example, a higher layer index is configuredfor each CORESET when applicable. The higher layer index is associatedwith a PUCCH resource group based on RRC signaling.

In one implementation, a single default spatial domain transmissionfilter may be used for transmissions of all PUCCH resources allocated tothe UE.

In one implementation, the default spatial domain transmission filtermay be a default TCI or QCL assumption for a PDSCH:

-   -   when one or more CORESET(s) are configured on a CC, the CORESET        with the lowest ID in the most recent monitored downlink slot;    -   when any CORESET is not configured on the CC, the activated TCI        state with the lowest II) applicable to the PDSCH in the active        DL-BWP of the CC;    -   when there is no activated TCI state for the PDSCH associated        with the scheduled cell.        -   In one example, a same spatial domain filter as the last            PRACH transmission may be used as a default spatial domain            transmission filter. The method may be applied when there is            no intra-band CC(s) with neither CORESET configuration nor            activated TCI for PDSCH.        -   In another example, a same spatial domain filter as the last            PUSCH transmission containing msg-3 may be used as a default            spatial domain transmission filter. The method may be            applied when there is no intra-band CC(s) with neither            CORESET configuration nor activated TCI for PDSCH.        -   In yet another example, the default spatial domain            transmission filter may correspond to a default TCI or QCL            assumption of a PDSCH of another intra-band component            carrier, for example, as the first two “in case” items            above, in this section.            -   In one embodiment, the lowest-indexed intra-band CC is                selected.            -   In one embodiment, the lowest-indexed intra-band CC with                CORESET(s) configuration is selected.            -   In one embodiment, the lowest-indexed intra-band CC with                activated TCI for PDSCH is selected.            -   In one embodiment, the lowest-indexed intra-band CC with                either CORESET(s) configuration or activated TCI for                PDSCH is selected.

In one implementation, the default spatial domain transmission filterfor a PUCCH resource may follow the QCL parameter(s) of a CORESET, wherethe CORESET may be used for DL PDCCH monitoring.

In one implementation, the CORESET may be associated with a CORESETgroup.

In one implementation, the CORESET group may be associated with a TRP(transmit-receive point).

In one implementation, the CORESET may or may not correspond to a DL CCthat is paired with the UL CC where the PUCCH resource resides. Forexample, the transmission on the PUCCH resource may be triggered by DCI,where a carrier indication field in the DCI may identify the UL CC.

In one implementation, a PUCCH resource may be associated with theCORESET by a BS via implicit/explicit signaling. For example, the PUCCHresource may be associated with (or included in) a PUCCH resource group.The BS may associate the PUCCH resource group with a CORESET group(including the CORESET) by mapping the PUCCH resource group to theCORESET group via NW signaling.

In one implementation, the CORESET may be associated with a monitoredsearch space with the lowest CORESET-ID in the latest slot in which theassociated CORESET group (including the CORESET) is monitored by the UE.In one example, the associated CORESET group may include all configuredCORESETs in the active BWP of a serving cell (or a CC). In anotherexample, the transmission on the PUCCH resource may correspond to aninstance of a P/SP PUCCH transmission.

In one implementation, the CORESET may be associated with a search spaceon which the DCI that triggers the transmission on the PUCCH resource isreceived by the UE. For example, the transmission on the PUCCH resourcetransmission may correspond to an AP PUCCH transmission.

In one implementation, the CORESET may be preconfigured/predetermined.In one example, the CORESET is predetermined as having a higher orlowest CORESET-ID index in the active DL BWP in the CC.

In one implementation, the RS associated with the QCL-type D in the QCLparameters of the CORESET may be used to determine the default spatialdomain transmission filter. In one implementation, the RS may be apathloss reference RS. For example, when the spatial domain transmissionfilter for PUCCH transmission is not provided by NW signaling via thePUCCH-SpatialRelationInfo IE, the pathloss reference RS for UL powercontrol of the PUCCH transmission may be determined as:

-   -   the RS indicated by the QCL parameter(s) of the CORESET (if        there are multiple RSs indicated by the QCL parameters, the RS        associated with the QCL-type D may be selected); or    -   a preconfigured RS.

In one implementation, for determining a default spatial domaintransmission filter for the transmission on a PUCCH resource (or a“PUCCH transmission”) when the corresponding thePUCCH-SpatialRelationInfo IE of the PUCCH resource is not provided bythe NW signaling, the PUCCH resource may be associated with (or includedin) a PUCCH resource group, where the PUCCH resource group may beassociated with a CORESET group. In this case, the default spatialdomain transmission filter for the transmission on the PUCCH resourcemay be determined based on the QCL parameter(s) of the CORESETassociated with a monitored search space with the lowest CORESET-ID inthe latest slot in which the CORESET group is monitored by the UE, ifthe PUCCH resource is for a P/SP transmission. In one implementation,the default spatial domain transmission filter for the transmission onthe PUCCH resource may be determined based on the QCL parameter(s) ofthe CORESET associated with a search space on which the DCI thattriggers the transmission on the PUCCH resource is received, if thePUCCH-resource is for an AP transmission.

In one implementation, if there is more than one RS associated with theQCL parameter(s), the RS associated with the QCL-type D may be used todetermine the default spatial domain transmission filter for a PUCCHresource. In one example, for power control of the transmission on thePUCCH resource, the pathloss reference RS may be used as the defaultspatial domain transmission filter.

2. Default Spatial Relation for SRS

The usage of an SRS resource set may be configured as one of{beamManagement, codebook, nonCodebook, antennaSwitching} as specifiedin the 3GPP NR specification, e.g., TS 38.331 V15.5.0. Each SRS resourcemay be RRC-configured by a BS with an SRS-SpatialRelationInfo IE fordetermining its spatial domain transmission filter for the ULtransmission. For each SRS resource set, a (DL) pathloss reference RSresource (e.g., indicated by an IE denoted as pathlossReferenceRS) maybe provided for estimating the DL pathloss for UL SRS power controlpurposes.

FIG. 2 illustrates multiple SRS resource sets each configured with a(DL) pathloss reference RS resource, in accordance with animplementation of the present disclosure.

As illustrated in FIG. 2 , a UE may be provided (or configured) withseveral SRS resource sets (e.g., including an SRS resource set 210 andan SRS resource set 220). Each SRS resource set may be associated with(or include) one or more SRS resources. For example, the SRS resourceset 210 may include M SRS resources (e.g., the SRS resource #1 212, theSRS resource #2 214, and the SRS resource #2 216), and the SRS resourceset 220 may include K SRS resources (e.g., the SRS resource #1 224, theSRS resource #2 226, and the SRS resource #2 228), where M and K arenatural numbers. Each SRS resource in an SRS resource set may beconfigured with a spatial domain transmission filter (e.g., indicated bythe SRS-SpatialRelationInfo IE). For example, if the correspondingSRS-SpatialRelationInfo IE is provided, an SRS resource may betransmitted based on a spatial domain transmission filter indicated bythe corresponding SRS-SpatialRelationInfo IE.

In addition, each SRS resource set may be configured with a pathlossreference RS resource (e.g., indicated by the pathlossReferenceRS IE).As illustrated in FIG. 2 , the SRS resource set 210 may be configuredwith the pathloss reference RS resource #1 218, and the SRS resource set222 may be configured with the pathloss reference RS resource #2 222.

An SRS resource may be used in a P/SP/AP manner. For example, an AP SRStransmission may be triggered by DCI, where the DCI may betransmitted 1) in a DL CC paired with an UL CC where the AP SRStransmission takes place, or 2) in a DL CC not paired with the UL CCwhere the AP PUCCH transmission takes place. In this case, SULoperation(s) may be considered as scenario 1) described above, forexample.

In the following subsections, methods for determining a default spatialdomain transmission filter for transmission(s) on an SRS resource areprovided. For ease of illustration, an SRS resource with the usage ofits associated SRS resource set being configured as “codebook” may bereferred to as an “SRS-codebook resource.” an SRS resource with theusage of its associated SRS resource set being configured as“nonCodebook” may be referred to as an “SRS-nonCodebook resource,” andan SRS resource with the usage of its associated SRS resource set beingconfigured as “antennaSwitching” may be referred to as an“SRS-antennaSwitching resource.” For example, if the usage of the SRSresource set 210 illustrated in FIG. 2 is configured as “nonCodebook.”the SRS resources 212, 214, and 216 associated with (or included in) theSRS resource set 210 are SRS-nonCodebook resources.

2.1 SRS-nonCodebook Resource

In one implementation, there may be 1, 2, 3, or 4 SRS-nonCodebookresources being configured in a corresponding resource set. In addition,there may be an associatedCSI-RS IE being configured in anSRS-nonCodebook resource set. In this case, the spatial domaintransmission filter for an SRS-nonCodebook resource may be determinedbased on explicit NW signaling via the associatedCSI-RS IE or theSRS-SpatialRelationInfo IE, but the NW may not provide both to the UE atthe same time.

In one implementation, the spatial domain transmission filter for anSRS-nonCodebook resource may be determined without NW explicitsignaling. For example, a default spatial domain transmission filter maybe applied by a UE when, for example, neither the associatedCSI-RS IEnor the SRS-SpatrialRelationInfo IE can be acquired from the NWsignaling.

In one implementation, the default spatial domain transmission filter(s)for individual SRS-nonCodebook resources allocated to a UE may bedetermined independently.

In one implementation, the SRS-nonCodebook resources allocated to the UEmay be grouped as one or more SRS-nonCodebook resource sets (e.g., theSRS resource sets 210 and 220 illustrated in FIG. 2 ). In this case, adefault spatial domain transmission filter may be determined for anSRS-nonCodebook resource set. For example, an SRS-nonCodebook resourceset may correspond to a LE panel, and multiple SRS-nonCodebook resourcesets may be configured for mapping to multiple UE panels.

In one implementation, the default spatial domain transmission filtermay be a default TCI or QCL assumption of a PDSCH:

-   -   when one or more CORESET(s) are configured on a CC, the CORESET        with the lowest ID in the most recent monitored downlink slot;    -   when any CORESET is not configured on the CC, the activated TCI        state with the lowest ID applicable to the PDSCH in the active        DL-BWP of the CC;    -   when there is no activated TCI state for the PDSCH associated        with the scheduled cell.        -   In one example, a same spatial domain filter as the last            PRACH transmission may be used as default spatial domain            transmission filter. The method may be applied when there is            no intra-band CC(s) with neither CORESET configuration nor            activated TCI for PDSCH.        -   In another example, a same spatial domain filter as the last            PUSCH transmission containing msg-3 may be used as a default            spatial domain transmission filter. The method may be            applied when there is no intra-band CC(s) with neither            CORESET configuration nor activated TCI for PDSCH.        -   In yet another example, the default spatial domain            transmission filter may correspond to a default TCI or QCL            assumption of a PDSCH of another intra-band component            carrier, for example, as the first two “in case” items            above, in this section.            -   In one embodiment, the lowest-indexed intra-band CC is                selected.            -   In one embodiment, the lowest-indexed intra-band CC with                CORESET(s) configuration is selected.            -   In one embodiment, the lowest-indexed intra-band CC with                activated TCI for PDSCH is selected.            -   In one embodiment, the lowest-indexed intra-band CC with                either CORESET(s) configuration or activated TCI for                PDSCH is selected.

In one implementation, the default spatial domain transmission filterfor an SRS-nonCodebook resource may follow the QCL parameter(s) of aCORESET, where the CORESET is for DL PDCCH monitoring.

In one implementation, the CORESET may be associated with a CORESETgroup.

In one implementation, the CORESET group may be associated with a TRP.

In one implementation, the CORESET may or may not correspond to a DL CCthat is paired with the UL CC where the SRS-nonCodebook resourceresides. For example, the transmission on the SRS-nonCodebook resourcemay be triggered by DCI, where a carrier indication field in the DCI mayidentify the UL CC.

In one implementation, the SRS-nonCodebook resource may be associatedwith the CORESET by the NW via implicit/explicit signaling. For example,the SRS-nonCodebook resource set associated with (or including) theSRS-nonCodebook resource may map to a CORESET group associated with (orincluding) the CORESET by NW signaling.

In one implementation, the CORESET may be associated with a monitoredsearch space with the lowest CORESET-ID in the latest slot in which theassociated CORESET group (e.g., including the CORESET) are monitored bythe UE. In one example, the associated CORESET group may include allconfigured CORESETs in the DL active BWP of a serving cell (or a CC). Inone example, the transmission on the SRS-nonCodebook resource maycorrespond to an instance of P/SP SRS transmission.

In one implementation, the CORESET may be associated with a search spaceon which the DCI that triggers the transmission on the SRS-nonCodebookresource is received by the UE. For example, the transmission on theSRS-nonCodebook resource transmission may correspond to an AP SRStransmission.

In one implementation, the CORESET may be preconfigured/predetermined.In one example, the CORESET may be predetermined/preconfigured as theone with the highest or the lowest CORESET-ID in the active DL BWP inthe CC.

In one implementation, the default spatial domain transmission filtermay follow the QCL parameter(s) of the PathlossReferenceRS IE configuredfor the associated SRS-nonCodebook resource set, if the UE is providedwith the PathlossReferenceRS IE.

In one implementation, the RS associated with the QCL-type D in the QCLparameter(s) of the CORESET may be used to determine the default spatialdomain transmission filter.

In one implementation, the default spatial domain transmission filter ofan SRS-nonCodebook resource may follow the spatial domain transmissionfilter (e.g., indicated by the PUCCH-SpatialRelationInfo IE) of a PUCCHresource with the lowest PUCCH resource II) (e.g., PUCCH-ResourceId)within the active UL BWP of the serving cell that the SRS-nonCodebookresource resides. The PUCCH resource with the lowest PUCCH-ResourceIdmay be selected from the PUCCH resources whose spatial relationinformation has been activated by MAC-CE signaling.

In one implementation, when the PathlossReferenceRS IE is not providedby NW signaling for the associated SRS-nonCodebook resource set (e.g.,in a case that the SRS resource set 210 illustrated in FIG. 2 is notconfigured with the pathloss reference RS resource #1 218), the pathlossreference RS for UL power control of the SRS-nonCodebook resourcetransmission may be determined as:

-   -   the RS indicated by the QCL parameter(s) of the CORESET (if        there are multiple RSs indicated by the QCL parameters, the RS        associated with the QCL-type D may be selected);    -   a CSI-RS (e.g., indicated by the associatedCSI-RS IE) associated        with the corresponding SRS-nonCodebook resource set; or    -   a preconfigured RS.

In one implementation, for determining a default spatial domaintransmission filter for the transmission on an SRS-nonCodebook resourcewhen the SRS-SpatialRelationInfo IE corresponding to the SRS-nonCodebookand the associatedCSI-RS IE corresponding to the SRS-nonCodebook are notprovided by the NW signaling, the SRS-nonCodebook resource set includingthe SRS-nonCodebook resource may be associated with a CORESET group. Inthis case, the default spatial domain transmission filter for thetransmission on the SRS-nonCodebook resource may be determined based onthe QCL parameter(s) of the CORESET associated with a monitored searchspace with the lowest CORESET-ID in the latest slot in which the CORESETgroup are monitored by the UE, if the SRS-nonCodebook resource is for aP/SP transmission. In one implementation, if the SRS-nonCodebookresource is for an AP transmission, the default spatial domaintransmission filter for the transmission on the SRS-nonCodebook resourcemay be determined based on the QCL parameter(s) of the CORESETassociated with a search space on which the DCI that triggers thetransmission on the SRS-nonCodebook resource is received.

In one implementation, if there is more than one RS associated with theQCL parameter(s), the RS associated with the QCL-type D may be appliedfor determining the default spatial domain transmission filter.

In one implementation, for power control of the transmission on anSRS-nonCodebook resource, when a UE is not configured with a pathlossreference RS for the corresponding SRS-nonCodebook resource set (e.g.,in a case that the UE is not configured with the PathlossReferenceRS IEfor the corresponding SRS-nonCodebook resource set), a pathlossreference RS may be determined as the default spatial domaintransmission filter for the corresponding SRS-nonCodebook resource.

2.2 SRS-Codebook Resource(s) and SRS-antennaSwitching Resource(s)

In one implementation, there may be 1 or 2 SRS-codebook resources beingconfigured in a corresponding resource set. A UE may determine a spatialdomain transmission filter for an SRS-codebook resource and for anSRS-antennaSwitching resource without being explicitly indicated by theNW. In addition, a default spatial domain transmission filter may beapplied when, for example, the UE cannot acquire theSRS-SpatialRelationInfo IE from the NW signaling. In the following, forease of illustration, an SRS resource that is either an SRS-codebookresource or an SRS-antennaSwitching resource may be denoted as an“SRS-ac resource.”

In one implementation, the default spatial domain transmission filter(s)for individual SRS-ac resources allocated to a UE may be determinedindependently.

In one implementation, the default spatial domain transmission filtermay be configured by the BS based on an SRS-ac resource set basis.

In one implementation, if only a subset of SRS-ac resources in an SRS-acresource set is not configured with the SRS-SpatialRelationInfo IE, thedefault spatial domain transmission filter may be applicable to thesubset of SRS-ac resources.

In one implementation, the methods for determining default spatialdomain transmission filter(s) may only be applicable when each SRS-acresource in an SRS-ac resource set is not configured with anSRS-SpatialRelationInfo IE.

In one implementation, an SRS-ac resource set may be associated with aUE panel.

In one implementation, the default spatial domain transmission filtermay be a default TCI or QCL assumption for a PDSCH:

-   -   when one or more CORESET(s) are configured on a CC, the CORESET        with the lowest ID in the most recent monitored downlink slot;    -   when any CORESET is not configured on the CC, the activated TCI        state with the lowest ID applicable to the PDSCH in the active        DL-BWP of the CC;    -   when there is no activated TCI state for the PDSCH associated        with the scheduled cell.        -   In one example, a same spatial domain filter as the last            PRACH transmission may be used as default spatial domain            transmission filter. The method may be applied when there is            no intra-band CC(s) with neither CORESET configuration nor            activated TC for PDSCH.        -   In another example, a same spatial domain filter as the last            PUSCH transmission containing msg-3 may be used as default            spatial domain transmission filter. The method may be            applied when there is no intra-band CC(s) with neither            CORESET configuration nor activated TCI for PDSCH.        -   In yet another example, the default spatial domain            transmission filter may correspond to a default TC or QCL            assumption of a PDSCH of another intra-band component            carrier, for example, as the first two “in case” items            above, in this section.            -   In one embodiment, the lowest-indexed intra-band CC is                selected.            -   In one embodiment, the lowest-indexed intra-band CC with                CORESET(s) configuration is selected.            -   In one embodiment, the lowest-indexed intra-band CC with                activated TCI for PDSCH is selected.            -   In one embodiment, the lowest-indexed intra-band CC with                either CORESET(s) configuration or activated TCI for                PDSCH is selected.

In one implementation, the default spatial domain transmission filter ofan SRS-ac resource may follow the QCL parameter(s) of a CORESET for DLPDCCH monitoring.

In one implementation, the CORESET may be associated with a CORESETgroup.

In one implementation, the CORESET group may be associated with a TRP.

In one implementation, the CORESET may or may not correspond to a DL CCthat is paired with the UL CC where the SRS-ac resource resides. Forexample, the transmission on the SRS-ac resource may be triggered byDCI, where a carrier indication field in the DCI may identify the UL CC.

In one implementation, an SRS-ac resource may be associated with theCORESET by NW via implicit or explicit signaling. For example, theSRS-ac resource set associated with (or including) the SRS-ac resourcemay map to a CORESET group associated with (or including) the CORESET byNW signaling.

In one implementation, the CORESET may be associated with a monitoredsearch space with the lowest CORESET-ID in the latest slot in which anassociated CORESET group (including the CORESET) is monitored by the UE.

In one implementation, the associated CORESET group may include allconfigured CORESETs in the DL active BWP of a serving cell for a CC).

In one implementation, the transmission on the SRS-ac resource maycorrespond to an instance of a P/SP SRS transmission.

In one implementation, the CORESET may be associated with a search spaceon which the DCI that triggers the transmission on the SRS-ac resourceis received.

In one implementation, the transmission on the SRS-ac resourcetransmission may correspond to an AP SRS transmission.

In one implementation, the CORESET may be preconfigured/predetermined.In one example, the CORESET is predetermined as the one with a higher orlowest CORESET-ID index in the active DL BWP in the CC.

In one implementation, the default spatial domain transmission filterfor an SRS-ac resource may follow the QCL parameter(s) of thePathlossReferenceRS IE of the associated SRS-nonCodebook resource set(including the SRS-ac resource), if the UE is configured with thePathlossReferenceRS IE.

In one implementation, the RS associated with the QCL-type D in the QCLparameter(s) may be used as a default spatial domain transmission filterfor an SRS-ac resource.

In one implementation, the default spatial domain transmission filter ofan SRS-ac resource may follow the spatial domain transmission filter(e.g., determined by the PUCCH-SpatialRelationInfo IE) of the PUCCHresource with the lowest PUCCH-ResourceId within the active UL BWP ofthe serving cell where the SRS-ac resource resides.

In one implementation, when the PathlossReferenceRS IE is not providedby NW signaling for the associated SRS-ac resource set, a pathlossreference RS for UL power control for the SRS-ac resource transmissionmay be determined as:

-   -   the RS indicated by the QCL parameters of the CORESET (if there        are multiple RSs indicated by the QCL parameters, the RS        associated with QCL-type D may be selected); or    -   a preconfigured RS.

In one implementation, for determining a default spatial domaintransmission filter for the transmission on an SRS-ac resource when theSRS-SpatialRelationInfo IE corresponding to the SRS-ac resource is notprovided by the NW signaling, the SRS-ac resource set (including theSRS-ac resource) may be associated with a CORESET group. In this case,the default spatial domain transmission filter for the transmission onthe SRS-ac resource may be determined based on the QCL parameter(s) ofthe CORESET associated with a monitored search space with the lowestCORESET-ID in the latest slot in which the CORESET group is monitored bythe UE, if the SRS-nonCodebook resource is for a P/SP transmission. Inone implementation, the default spatial domain transmission filter forthe transmission on the SRS-nonCodebook resource may be determined basedon the QCL parameter(s) of the CORESET associated with a search space onwhich the DCI that triggers the transmission on the SRS-ac resource isreceived, if the SRS-ac resource is for an AP transmission.

In one implementation, if there is more than one RS associated with theQCL parameter(s), the RS associated with the QCL-type D may be appliedfor determining the default spatial domain transmission tilter.

In one implementation, for power control of the transmission on theSRS-ac resource when the PathlossReferenceRS IE is not configured forthe corresponding SRS-ac resource set, a pathloss reference RS may beused as the default spatial domain transmission filter for the SRS-acresource.

3. Default Spatial Relation for PUSCH

For a DCI format 0_0 based PUSCH scheduling based on Rel-15 NR asspecified in TS 38 series specifications (e.g., TS 38.213 V15.6.0 and TS38.214 V15.6.0), spatial relation information for a PUSCH transmissionis not explicitly indicated in the scheduling DCI. Instead, the UEtransmits the PUSCH according to the spatial relation, if applicable,corresponding to the dedicated PUCCH resource with the lowest ID withinthe active UL BWP of the cell as described in 9.2.1 TS 38.213 e.g.,V15.6.0. For this reason, the UE does not expect a PUSCH scheduled by aDCI format 0_0 in a BWP without a configured PUCCH resource withPUCCH-SpatialRelationInfo in the frequency range 2 (FR2) in an RRCconnected mode. This may be applicable to a frequency range higher thanthe frequency range 1 (FR1), but not included in frequency range 2 aswell.

For a DCI format 0 . . . 1 based PUSCH scheduling based on Rel-15 NR asspecified in TS 38 series specifications (e.g., TS 38.213 V15.6.0 and TS38.214 V15.6.0), spatial relation information for a PUSCH transmissionis explicitly indicated in the scheduling DCI. Specifically, a DCI field“SRS resource indicator” may provide spatial relation information for ascheduled PUSCH.

3.1 Default Spatial Relation for DCI Format 0_0 Scheduled PUSCH

In various implementations under this section, a UE may be configuredwith one or more PUCCH resources, but none of the configured PUCCHresources is provided with any corresponding PUCCH-SpatialRelationInfo.When a PUCCH resource is referred for determining a spatial relation,but a PUCCH-SpatialRelationInfo IE is not configured for the PUCCHresource, a default spatial relation for a PUSCH scheduled by a DCIformat 0_0 is disclosed in this section. In one preferred example, thedefault spatial relation for the PUCCH as described in this section orSection 1 can be applied. For example, the default spatial relation maybe a default TCI or QCL assumption of PDSCH of a serving cell (CC):

-   -   when the CORESET(s) are configured on the CC, the CORESET        associated with a monitored search space with the lowest CORESET        ID in the most recent monitored downlink slot within the active        BWP of the CC;    -   when no CORESETs are configured on the CC, the activated TCI        state with the lowest ID applicable to PDSCH in the active        DL-BWP of the CC.

In some implementations, there may be cases where no activated TCstate(s) is available within a CC so that there is no “activated TCIstate” to be referred to. For example, it may happen that after initialaccess procedure, no TCI state configuration or no TCI state activationMAC-CE command has been received yet. The case may also happen after ahandover. There may also be cases where among multiple CCs in dualconnectivity or carrier aggregation scenario, one or multiple CCs arenot provided with CORESET or TCI state configuration. In these cases, adefault spatial relation for an SRS or for a PUCCH (and thus, may beapplied for PUSCH scheduled by 0_0 as well) may be determined by:

-   -   a same spatial domain filter as the last PRACH transmission may        be used as default spatial relation.        -   In one example, the last PRACH may be from the same CC.        -   In another example, the last PRACH may be from SpCell.        -   In yet another example, the last PRACH may be from a            intra-band CC.    -   a same spatial domain filter as the last PUSCH transmission        containing msg-3 may be used as default spatial relation.        -   In one example, the last msg-3 PUSCH may be from the same            CC.        -   In another example, the last msg-3 PUSCH may be from SpCell.        -   In yet another example, the last msg-3 PUSCH may be from an            intra-band CC.    -   the default spatial relation may correspond to a default TCI or        QCL assumption of PDSCH of another intra-band component carrier        (CC).        -   In one example, the lowest-indexed intra-band CC with            CORESET(s) configuration is selected.        -   In another example, the lowest-indexed intra-band CC with            either CORESET s) configuration or activated TCI for PDSCH            is selected.

In various implementation of the present disclosure, the default spatialrelation is subject to the UE's capability and/or base station'ssignaling (e.g., gNB signaling). The UE capability at least indicates NRRel-16 compatible UE, as specified in 3GPP TR 38 series specifications.The capability may further indicate the support of a default spatialrelation for a PUCCH and/or an SRS. The capability may further indicatethe support of a default spatial relation for a PUSCH scheduled by, forexample, DCI format 0_0. The capability may simply indicate the supportof a default spatial relation, and it may apply to PUCCH and SRS andPUSCH. In this sense, a legacy Rel-15 compatible UE may not expect to bescheduled by a DCI format 0_0 for a PUSCH transmission when aPUCCH-SpatialRelationInfo IE is not configured for the PUCCHresource(s).

If the PUCCH-SpatialRelationInfo IE is not configured for a PUCCHresource(s), the following features are summarized to determine spatialrelation information for a PUSCH scheduled by a DCI format 0_0:

-   -   In one implementation, the UE applies a default spatial relation        applied for a PUCCH transmission for a PUSCH transmission.        -   The application of the default spatial relation may be            subject to the UE capability and/or gNB signaling.            -   The UE capability at least indicates it's an NR Rel-16                compatible UE. In one implementation, the capability may                further indicate the support of default spatial relation                for PUCCH and/or SRS. In one implementation, the                capability may further indicate the support of a default                spatial relation for PUSCH.            -   For a legacy Rel-15 compatible UE, the application of a                default spatial relation is not expected. The Rel-15 UE                does not expect to be scheduled by a DIX format 0_0 for                a PUSCH transmission when the PUCCH-SpatialRelationInfo                IE is not configured for a PUCCH resource(s).        -   The default spatial relation may be derived based on the            method(s) described in Section 1.    -   In one embodiment, the UE does not expect to be scheduled by a        DCI format 0_0 for a PUSCH transmission when the        PUCCH-SpatialRelationInfo IE is not configured for PUCCH        resource(s).

FIG. 3 illustrates a flowchart for a method 300 by a LE for defaultspatial relation information determination, in accordance with animplementation of the present disclosure.

In action 302, the UE may indicate to a cell (e.g., through RRCsignaling) of the UE's capability to support a default spatial relationbehavior for a PUCCH transmission or an SRS.

In action 304, the UE may indicate to the cell (e.g., through RRCsignaling) of the UE's capability to support a default spatial relationbehavior for a PUSCH.

In action 306, the UE may receive, from the cell, configurationsignaling configuring the UE with one or more PUCCH resources on anactive UL BWP. In the present implementation, the one or more PUCCHresources are not configured with beam information. For example,PUCCH-Spatial Relation Information (PUCCH-SpatialRelationInfo) is notindicated in the configuration signaling from the cell. In addition, theconfiguration signaling indicates to the LIE that that the defaultspatial relation behavior for PUSCH transmission scheduled by a DCIformat 0-0 is enabled.

In action 308, the UE may receive, from the cell, the DCI format 0_0 onan active DL BWP, the DCI format 0_0 providing scheduling informationfor a PUSCH.

In action 310, the UE may transmit, to the base station, the PUSCHaccording to the default spatial relation behavior. The default spatialrelation behavior determines a spatial relation with reference to aQCL-TypeD reference signal corresponding to a QCL assumption of apre-determined CORESET on the active DL BWP of the cell, when thedefault spatial relation behavior is enabled by the cell. In oneimplementation, the predetermined CORSET is configured with a lowest IDon the active DL BWP of the cell. In one implementation, thepredetermined CORESET is the same as a default spatial relation settingapplied for a PUCCH transmission from the UE, if at least one of theconditions is met: (i) the UE reports beam correspondence capability tothe cell; and (ii) the default spatial relation setting applied for thePUCCH transmission is enabled by the cell.

FIG. 4 illustrates a flowchart for a method 400 by a base station fordefault spatial relation information determination, in accordance withan implementation of the present disclosure.

In action 402, the base station may receive, from a LE (e.g., throughRRC signaling), an indication of the UE's capability to support adefault spatial relation behavior for a PUCCH transmission or an SRS.

In action 404, the base station may receive, from the UE (e.g., throughRRC signaling), an indication of the UE's capability to support adefault spatial relation behavior for a PUSCH.

In action 406, the base station may transmit, to the UE, configurationsignaling configuring the UE with one or more PUCCH resources on anactive UL BWP. In the present implementation, the one or more PUCCHresources are not configured with beam information. For example,PUCCH-Spatial Relation Information (PUCCH-SpatialRelationInfo) is notindicated in the configuration signaling from the cell. In addition, theconfiguration signaling indicates to the UE that that the defaultspatial relation behavior for PUSCH transmission scheduled by a DCIformat 0_0 is enabled.

In action 408, the base station may transmit, to the UE, the DCI format0_0 on an active downlink (DL) BWP, the DCI format 0 . . . providingscheduling information for the PUSCH.

In action 410, the base station may receive, from the UE, the PUSCHaccording to the default spatial relation behavior. The default spatialrelation behavior determines a spatial relation with reference to aQCL-TypeD reference signal corresponding to a QCL assumption of apre-determined CORESET on the active DL BWP of the cell, when thedefault spatial relation behavior is enabled by the cell. In oneimplementation, the predetermined CORSET is configured with a lowest IDon the active DL BWP of the cell. In one implementation, thepredetermined CORESET is the same as a default spatial relation settingapplied for a PUCCH transmission from the UE, if at least one of theconditions is met: (1) the UE reports beam correspondence capability tothe cell; and (2) the default spatial relation setting applied for thePUCCH transmission is enabled by the cell.

3.2 Default Spatial Relation for DCI Format 0_1 Scheduled PUSCH

For a DCI format 0_1 scheduling a PUSCH, spatial relation information isprovided via SRS with srs-SpatialRelationInfo configuration, (e.g., inan “SRS resource indicator (SRI)” field). The resource set usage of theSRS used for SRI indication is configured as either “codebook” or“nonCodebook”. In one example, the SRS with its resource set usageconfigured as “antennaSwitching” is applicable as well. When the SRSindicated by SRI is not configured with srs-SpaialRelationInfo, thefollowing features are summarized for determining default spatialrelation information for PUSCH scheduled by a DCI format 0_1:

-   -   In one implementation, the UE may ignore the indication in SRI        field.        -   The UE applies a default spatial relation applied for a            PUCCH transmission for a PUSCH transmission. The            determination of the default spatial relation may follow the            methods described in Section 1.            -   The method may be applied when none of dedicated PUCCH                resource(s) is configured with                PUCCH-SpatialRelationInfo.        -   The UE applies the spatial relation corresponding to the            dedicated PUCCH resource with the lowest PUCCH resource ID            within the active UL BWP of the cell.            -   The method may be applied when there are dedicated PUCCH                resource(s) configured with PUCCH-SpatialRelationInfo    -   In one implementation, the UE applies a default spatial relation        applied for the indicated SRS for a PUSCH transmission. The        determination of the default spatial relation may follow the        methods described in Section 2.        -   The SRS default spatial relation is associated with            “codebook” or “nonCodebook” usage.

In various implementations of the present disclosure, methods fordetermining a default spatial relation for a PUCCH/SRS/PUSCHtransmission are discussed. For the PUCCH default spatial relation, itis assumed that no PUCCH-SpatialRelationInfo is provided for PUCCHresources. For SRS default spatial relation, it is assumed that nosrs-SpatialRelationInfo is provided. For default spatial relation forPUSCH associated with a DCI format 0_0, it is assumed noPUCCH-SpatialRelationInfo is provided. For default spatial relation forPUSCH associated with a DCI format 0_1, it is assumed nosrs-SpatialRelationInfo is provided.

For PUCCH and SRS default special relation determination, scenarioswhere no activated TCI state(s) and/or during multiple CC operation areaddressed. In this case, default spatial relation may be derived basedon CORESET(s) or activated TC state(s) of an intra-band CC.

For PUSCH associated with DCI 0_0, default spatial relation informationmay be derived from PUCCH default spatial relation. Such application maybe subject to UE capability signaling.

For PUSCH associated with DCI 0_1, default spatial relation informationmay be derived from PUCCH default spatial relation or from SRS defaultspatial relation, depending on whether PUCCH-SpatialRelationInfo isprovided or not.

In one implementation, the UE may transmit, to a BS, a UE capabilitymessage indicating that beam correspondence is supported by the UE. Ifthe UE supports beam correspondence, it may mean that the UE has theability to, for example, select a suitable beam for UL transmissionbased on DL measurements with or without relying on UL beam sweeping.

The following provides non-limiting descriptions of certain terms.

Beam Failure Recovery: movements in the environment or other events, maylead to a currently established beam pair being rapidly blocked withoutsufficient time for the regular beam adjust to adapt based on the beamreporting mechanism (the beam reporting mechanism may be similar to theCSI reporting mechanism taken place in the Physical (PHY) channels). Abeam failure recovery procedure may be used to deal with suchoccurrences with a short reaction time.

Beam: the term “beam” here may be replaced by “spatial domaintransmission filter.” For example, when a UE reports a preferred gNB Txbeam, the UE is essentially selecting a spatial filter used by the gNB.The term “beam information” may be used to provide information aboutwhich beam/spatial domain transmission filter is being used/selected. Inone implementation, individual RSs may be transmitted by applyingindividual beams (spatial domain transmission filters). Thus, the term“beam” or “beam information” may be represented by RS resource index(es)in some implementations of the present disclosure.

HARQ: A functionality ensures delivery between peer entities at Layer 1(e.g., the PHY Layer). A single HARQ process may support one TransportBlock (TB) when the PHY layer is not configured for DL/UL spatialmultiplexing, and when the PHY layer is configured for DL/UL spatialmultiplexing, a single HARQ process may support one or multiple TBs. Inone implementation, there may be one HARQ entity per serving cell. EachHARQ entity may support a parallel (number) of DL and UL HARQ processes.

Timer: A MAC entity may setup one or more timers for individualpurposes, for example, triggering some UL signaling retransmissions orlimiting some UL signaling retransmission periods. A timer is runningonce it is started, until it is stopped or until it expires; otherwiseit is not running. A timer can be started if it is not running orrestarted if it is running. A timer is always started or restarted fromits initial value. The initial value may be but not limited to beconfigured by a BS (e.g., gNB) via DL RRC signaling.

BWP: A subset of the total cell bandwidth of a cell is referred to as aBWP. Bandwidth adaptation may be achieved by configuring a UE withBWP(s) and telling the UE which of the configured BWPs is currently theactive one. To enable Bandwidth Adaptation (BA) on the PCell, a gNB mayconfigure the LE with UL and DL BWP(s). To enable BA on SCells in caseof Carrier Aggregation (CA), the gNB may configure the UE with DL BWP(s)at least (e.g., there may be none in the UL). For the PCell, the initialBWP may be the BWP used for initial access. For the SCell(s), theinitial BWP may be the BWP configured for the UE to first operate atSCell activation. A UE may be configured with a first active UL BWP by afirstActiveUplinkBWP IE. If the first active UL BWP is configured for anSpCell, the firstActiveUplinkBWP IE field may contain the ID of the ULBWP to be activated upon the UE performing the RRC (re-)configurationprocess. If the field is absent, the RRC (re-)configuration process maynot impose a BWP switch. If the first active UL BWP is configured for anSCell, thefirstActiveUplinkBWP IE field may contain the ID of the UL BWPto be used upon MAC-activation of an SCell.

QCL: Two antenna ports are quasi co-located if properties of the channelover which a symbol on one antenna port is conveyed can be inferred fromthe channel over which a symbol on the other antenna port is conveyed.The “properties of the channel” described above may include at least oneof Doppler shift, Doppler spread, average delay, delay spread, andspatial Rx parameters. These properties may be categorized intodifferent QCL types in NR TSs. For example, the QCL-type D refers to aspatial Rx parameter. The QCL-type D may be referred to as a “beam.”

TCI state: a TCI state may contain parameters for configuring a QCLrelationship between one or two DL RSs and a target RS set. For example,a target RS set may be the DM-RS ports of a PDSCH or a PDCCH.

Normal Scheduling Request (SR): A normal SR may be used for requestingan UL Shared Channel (UL-SCH) resource (e.g., a PUSCH resource) for newtransmission. The UE may be configured with zero, one, or more than onenormal SR configuration. A normal SR configuration may include a set ofPUCCH resources for SR across different BWPs and cells. For a logicalchannel, at most one PUCCH resource for SR may be configured per BWP.Each normal SR configuration may correspond to one or more logicalchannels. Each logical channel may be mapped to zero or one normal SRconfiguration. The normal SR configuration of the logical channel thattriggered a Buffer Status Report (BSR) procedure (if the configurationof the BSR procedure exists) may be considered as the correspondingnormal SR configuration for the triggered SR procedure. When a normal SRprocedure is triggered, the normal SR procedure may be considered aspending until it is canceled.

Beam Correspondence: beam correspondence is the ability of a UE toselect a suitable beam for UL transmission based on DL measurements withor without relying on UL beam sweeping. Alternatively, beamcorrespondence may be referred to as the ability of a UE to be indicateda suitable beam for DL reception based on the UL beam sweepingprocedure.

FIG. 5 illustrates a block diagram of a node 500 for wirelesscommunication, in accordance with various aspects of the presentdisclosure. As illustrated in FIG. 5 , the node 500 may include atransceiver 506, a processor 508, a memory 502, one or more presentationcomponents 504, and at least one antenna 510. The node 500 may alsoinclude a Radio Frequency (RF) spectrum band module, a BS communicationsmodule, an NW communications module, and a system communicationsmanagement module. Input/Output (I/O) ports, I/O components, and powersupply (not explicitly illustrated in FIG. 5 ). Each of these componentsmay be in communication with each other, directly or indirectly, overone or more buses 524. In one implementation, the node 500 may be a UEor a BS that performs various functions described herein, for example,with reference to FIGS. 1 through 4 .

The transceiver 506 having a transmitter 516 (e.g.,transmitting/transmission circuitry) and a receiver 518 (e.g.,receiving/reception circuitry) may be configured to transmit and/orreceive time and/or frequency resource partitioning information. In oneimplementation, the transceiver 506 may be configured to transmit indifferent types of subframes and slots, including, but not limited to,usable, non-usable and flexibly usable subframes and slot formats. Thetransceiver 506 may be configured to receive data and control channels.

The node 500 may include a variety of computer-readable media.Computer-readable media can be any available media that can be accessedby the node 500 and include both volatile (and non-volatile) media andremovable (and non-removable) media. By way of example, and notlimitation, computer-readable media may include computer storage mediaand communication media. Computer storage media may include bothvolatile (and non-volatile) and removable (and non-removable) mediaimplemented according to any method or technology for storage ofinformation such as computer-readable.

Computer storage media includes RAM, ROM, EEPROM, flash memory (or othermemory technology), CD-ROM, Digital Versatile Disks (DVD) (or otheroptical disk storage), magnetic cassettes, magnetic tape, magnetic diskstorage (or other magnetic storage devices), etc. Computer storage mediadoes not include a propagated data signal. Communication media maytypically embody computer-readable instructions, data structures,program modules, or other data in a modulated data signal such as acarrier wave or other transport mechanism and include any informationdelivery media. The term “modulated data signal” may mean a signal thathas one or more of its characteristics set or changed in such a manneras to encode information in the signal. By way of example, and notlimitation, communication media may include wired media such as a wiredNW or direct-wired connection, and wireless media such as acoustic, RF,infrared and other wireless media. Combinations of any of the aboveshould also be included within the scope of computer-readable media.

The memory 502 may include computer-storage media in the form ofvolatile and/or non-volatile memory. The memory 502 may be removable,non-removable, or a combination thereof. For example, the memory 502 mayinclude solid-state memory, hard drives, optical-disc drives, etc. Asillustrated in FIG. 5 , the memory 502 may store computer-readableand/or -executable instructions 514 (e.g., software codes) that areconfigured to, when executed, cause the processor 508 to perform variousfunctions described herein, for example, with reference to FIGS. 1through 4 . Alternatively, the instructions 514 may not be directlyexecutable by the processor 508 but may be configured to cause the node500 (e.g., when compiled and executed) to perform various functionsdescribed herein.

The processor 508 (e.g., having processing circuitry) may include anintelligent hardware device, a Central Processing Unit (CPU), amicrocontroller, an ASIC, etc. The processor 508 may include memory. Theprocessor 508 may process the data 512 and the instructions 514 receivedfrom the memory 502, and information through the transceiver 506, thebaseband communications module, and/or the NW communications module. Theprocessor 508 may also process information to be sent to the transceiver506 for transmission through the antenna 510, to the NW communicationsmodule for transmission to a CN.

One or more presentation components 504 may present data indications toa person or other device. Examples of presentation components 504 mayinclude a display device, speaker, printing component, vibratingcomponent, etc.

From the above description, it is manifested that various techniques maybe used for implementing the concepts described in the presentapplication without departing from the scope of those concepts.Moreover, while the concepts have been described with specific referenceto certain implementations, a person of ordinary skill in the art wouldrecognize that changes may be made in form and detail without departingfrom the scope of those concepts. As such, the described implementationsare to be considered in all respects as illustrative and notrestrictive. It should also be understood that the present applicationis not limited to the particular implementations described above. Still,many rearrangements, modifications, and substitutions are possiblewithout departing from the scope of the present disclosure.

1. A user equipment (UE), comprising: one or more non-transitorycomputer-readable media having computer-executable instructions embodiedthereon; and at least one processor coupled to the one or morenon-transitory computer-readable media, and configured to execute thecomputer-executable instructions to: receive, from a cell, configurationsignaling configuring the UE with one or more Sounding Reference Signal(SRS) resources on an active uplink (UL) Bandwidth part (BWP), the oneor more SRS resources not being configured with SRS—Spatial RelationInformation (SRS-SpatialRelationInfo), and the configuration signalingindicating that a default spatial relation behavior for SRS transmissionis enabled; and transmit the SRS according to the default spatialrelation behavior which determines a spatial relation with reference toa Quasi-CoLocation (QCL)-TypeD (QCL-TypeD) reference signal (RS)corresponding to a QCL assumption of a pre-determined Control ResourceSet (CORESET) on the active DL BWP of the cell.
 2. The UE of claim 1,wherein the predetermined CORESET is the same as a default spatialrelation setting applied for a Physical Uplink Control CHannel (PUCCH)transmission from the UE, if: the UE reports beam correspondencecapability to the cell; or the default spatial relation setting appliedfor the PUCCH transmission is enabled by the cell.
 3. The UE of claim 1,wherein the predetermined CORSET is configured with a lowest Identifier(ID) on the active DL BWP of the cell.
 4. The UE of claim 2, wherein theat least one processor is further configured to execute thecomputer-executable instructions to: indicate to the cell of the UE'scapability to support the default spatial relation behavior for a PUCCHtransmission or a Physical Uplink Shared CHannel (PUSCH).
 5. The UE ofclaim 1, wherein the at least one processor is further configured toexecute the computer-executable instructions to: indicate to the cell ofthe UE's capability to support the default spatial relation behavior forthe SRS.
 6. A method by a user equipment (UE), the method comprising:receiving, from a cell, configuration signaling configuring the UE withone or more Sounding Reference Signal (SRS) resources on an activeuplink (UL) Bandwidth part (BWP), the one or more SRS resources notbeing configured with SRS-Spatial Relation Information(SRS-SpatialRelationInfo), and the configuration signaling indicatingthat a default spatial relation behavior for SRS transmission isenabled; receiving, from the cell, the DCI format 0_0 on an activedownlink (DL) BWP, the DCI format 0_0 providing scheduling informationfor a PUSCH; and transmitting the SRS according to the default spatialrelation behavior which determines a spatial relation with reference toa Quasi-CoLocation (QCL)-TypeD (QCL-TypeD) reference signal (RS)corresponding to a QCL assumption of a pre-determined Control ResourceSet (CORESET) on the active DL BWP of the cell, when the default spatialrelation behavior is enabled by the cell.
 7. The method of claim 6,wherein the predetermined CORESET is the same as a default spatialrelation setting applied for a Physical Uplink Control CHannel (PUCCH)transmission from the UE, if: the UE reports beam correspondencecapability to the cell; or the default spatial relation setting appliedfor the PUCCH transmission is enabled by the cell.
 8. The method ofclaim 6, wherein the predetermined CORSET is configured with a lowestIdentifier (ID) on the active DL BWP of the cell.
 9. The method of claim7, further comprising: indicating to the cell of the UE's capability tosupport the default spatial relation for a PUCCH transmission or aPhysical Uplink Shared CHannel (PUSCH).
 10. The method of claim 6,further comprising: indicating to the cell of the UE's capability tosupport the default spatial relation behavior for the SRS.